JP2023552913A - Functionalized hydrogenated interpolymers containing non-hydrogenated polymer segments - Google Patents

Abstract

A functionalized polymer includes a hydrogenated interpolymer moiety, a non-hydrogenated polymer moiety, and a radical of a functional coupling agent covalently linked to these moieties. The functional group of the coupling agent exhibits interaction with silica. The interpolymer can include a vinyl aromatic mer and a conjugated diemer, with at least a portion of the conjugated diemer being hydrogenated, typically at least 50 mole percent. [Selection diagram] None

Description

(Cross reference to related applications)
This International Application claims the benefit of U.S. Provisional Patent Application No. 63/132,592, filed December 31, 2020, which is incorporated herein by reference in its entirety.

Rubber articles, such as tire components (e.g., treads, sidewalls, etc.), are often made from elastomeric compositions that include one or more reinforcing materials, such as particulate carbon black and silica, e.g., The Vanderbilt. Rubber Handbook, 13th ed. (1990), pp. See 603-04. Some of the most commonly used synthetic elastomeric materials used in the production of vulcanizates, such as tire components, include high-cis polybutadiene (BR), which is often produced by a catalyzed process. and substantially random styrene/butadiene interpolymers (SBR), which are produced by processes that often use anionic initiators.

While good traction and wear resistance are primary considerations for tire treads, automotive fuel efficiency considerations require minimizing rolling resistance, which correlates with reduced hysteresis and heat buildup during tire operation. ing. These considerations are competing and somewhat contradictory to a significant extent: treads made from compositions designed to provide good road traction typically exhibit increased rolling resistance. , and vice versa.

Fillers, polymers, and additives are typically selected to provide an acceptable compromise or balance of desired properties. Ensuring that the reinforcing filler is well dispersed throughout the elastomeric material serves to improve processability as well as improve physical properties. The dispersion of filler particles can be improved by increasing their interaction with the elastomer and/or decreasing their interaction with each other. Examples of this type of approach include high temperature mixing in the presence of selective reactivity promoters, surface oxidation of compounded materials, and surface grafting.

The portion of the polymer chain from the last crosslinking site to the end is not attached to the polymer network and therefore cannot participate in an efficient elastic recovery process. As a result, the energy transferred to this portion of the polymer (and the vulcanizate into which such polymer is incorporated) is lost as heat. Ensuring that these terminals are bonded to or otherwise sufficiently interact with the reinforcing particulate filler is important for many vulcanizates, e.g., reducing hysteresis. important for the physical properties of

Chemically modifying polymers, typically at their ends, is one of the most effective ways to increase filler-polymer interaction. Terminal chemical modification is often performed by reacting the living polymer with a functional terminator, e.g., U.S. Pat. No. 3,109,871; U.S. Pat. , No. 153, No. 5,109,907, No. 6,977,281, etc., as well as the references cited therein and subsequent publications that cite these patents. Post-polymerization end-functionalization that can be performed with anionically initiated polymers is often not possible with coordination catalyst polymers, and to a lesser extent vice versa.

Interest in hydrogenated polymers as components in rubber compositions continues to grow. These include hydrogenated BR (H-BR) and hydrogenated SBR (H-SBR). The latter typically exhibit improved tensile properties compared to otherwise equivalent SBR, especially when the degree of hydrogenation exceeds about 90%. (However, since a certain amount of residual unsaturation must remain in order to participate in the crosslinking reaction (vulcanization), the degree of hydrogenation cannot be 100%.)

However, it has become clear that the use of H-SBR has some limitations. H-SBR differs from the so-called bulk rubbers with which it is sometimes blended (e.g. SBR, BR, NR, etc.) because when the degree of hydrogenation exceeds about 90%, there are very few potential crosslinking sites left. May indicate curing speed. Hydrogenation also affects the solubility parameters of the polymer, which can lead to immiscibility with other unsaturated polymers in a given rubber composition.

Still desirable are H-SBRs that exhibit satisfactory compatibility and acceptable comparable cure rates when blended with one or more bulk rubbers. Preferably, the composition containing the H-SBR exhibits similar or superior tensile properties compared to a vulcanizate made from an otherwise equivalent composition that does not contain the H-SBR. Can be fed to sulfates.

Provided herein are functionalized polymers that include a hydrogenated interpolymer portion, a non-hydrogenated polymer portion, and a radical of a functional coupling agent covalently bonded to each of the portions. The functional group obtained from the binding of the coupling agent exhibits interaction with silica.

The interpolymer may advantageously include a vinyl aromatic mer and a conjugated diemer, with at least a portion of the conjugated diemer being hydrogenated, i.e., a condition in which _H2 can be added to a portion of its double bonds. As a result of exposure of the polymer to , some of the residual unsaturation obtained from the incorporation of such mer is lost. Compared to the total number of conjugated diemers incorporated into the interpolymer, the conjugated diemers that are hydrogenated, i.e., no longer contain ethylenic unsaturation, are typically at least 50 mol %, preferably significantly higher; For example, it comprises at least about 80 mole percent.

In some embodiments, the interpolymer can include 10-45 mole percent vinyl aromatic mer. In these and other embodiments, the interpolymer may have a significant percentage of its conjugated diemer incorporated in the 1,2-vinyl configuration, such as at least 30 mole percent.

The non-hydrogenated polymer portion of the macromolecule includes, and in some embodiments, consists of, a conjugated diemer. In embodiments where the non-hydrogenated polymeric portion consists of a conjugated diemer, the portion may have a number average molecular weight (M _n ) of up to about 50 kg/mol, often 10-40 kg/mol.

The radical covalently bonded to both polymeric moieties may be the residue of a coupling agent, the coupling agent containing a functional group that is reactive toward the carbanion and capable of interacting with the silica. groups that do not react or decompose when exposed to hydrogenation conditions. In some embodiments, functional coupling agents can include epoxy groups and siloxy groups.

Also provided are methods of providing the aforementioned functionalized polymers. An interpolymer comprising a vinyl aromatic mer, a conjugated diemer, and a terminal functional group obtained from an incorporated coupling agent is subjected to conditions in which a portion, preferably at least half, of the conjugated diemer is hydrogenated. It can be done. The interpolymer is or has been introduced into the carbanionic polymer containing the conjugated diemer, and the carbanionic polymer reacts with the radicals of the coupling agent previously covalently bonded only to the interpolymer. From 0.5 to 10 equivalents of the second type of polymer can be used per equivalent of interpolymer. The result is a polymer containing portions derived from both polymers.

Regardless of how they are characterized, polymers can interact with particulate fillers, especially silica. Compositions comprising particulate fillers and functionalized polymers are also provided, as are methods of providing and using such compositions.

The composition can include other elastomers. Advantageously, the functionalized polymer may exhibit improved miscibility with certain bulk rubbers commonly used in rubber compositions, particularly BR, as well as desirable tensile properties in vulcanizates obtained therefrom. can.

Other aspects of the invention will be apparent to those skilled in the art from the following detailed description. To aid in understanding the discussion, certain definitions are provided below and are intended to apply throughout unless surrounding text explicitly indicates a contrary intent.
"Polymer" means a polymerized product of one or more monomers and includes homopolymers, copolymers, terpolymers, tetrapolymers, and the like.
"Mer" or "mer unit" means a portion of a polymer that is derived from a single reactant molecule (eg, ethylene mer has the general formula -CH ₂ CH ₂ -).
"Copolymer" means a polymer that includes mer units derived from two reactants, typically monomers, and includes random copolymers, block copolymers, segmented copolymers, graft copolymers, and the like.
"Interpolymer" means a polymer containing mer units derived from at least two reactants, typically monomers, and includes copolymers, terpolymers, tetrapolymers, and the like.
"Random interpolymer" means mer units derived from each type of constituent monomer incorporated in an essentially non-repetitive manner and substantially free of blocks, i.e., segments of three or more of the same mer. means interpolymer.
"Gum Mooney viscosity" is the Mooney viscosity of the uncured polymer before the addition of any fillers.
"Substituted" means containing heteroatoms or functional groups (eg, hydrocarbyl groups) that do not interfere with the intended purpose of the group.
"Direct bond" means a covalent bond without intervening atoms or groups.
"Polyene" means a molecule having at least two double bonds in its longest portion or chain, and specifically includes dienes, trienes, and the like.
"Polydiene" means a polymer containing one or more diene mer units.
"Microstructure" refers to the individual characteristics or the totality of all such characteristics relating to the way the polyenemer is incorporated into the polymer chain, including 1,4-content, 1,2-(vinyl) content, Contains cis content and trans content.
"phr" means pbw per 100 parts by weight (pbw) of rubber.
"Radical" or "residue" means the portion of a molecule that remains after reacting with another molecule, whether atoms are gained or lost as a result of the reaction.
"Terminal" means the end of a polymer chain.
"Terminal part" means a group or functional group located at the terminal,
"Reactive polymer" means a polymer that has at least one site that readily reacts with other molecules due to the presence of an active end; the term includes, among others, carbanionic polymers.

Throughout this specification, all values expressed in percentage form are percentages by weight (w/w), unless the surrounding text explicitly indicates a contrary intent.

Unless stated otherwise in the surrounding text, all numbers expressing amounts of ingredients, process conditions (e.g. time and temperature), etc. are to be understood as modified in all cases by the term "about". It is. The enumerated numerical limitations include an appropriate degree of precision based on the number of significant digits used; for example, "up to 5.0" can be interpreted to set an absolute upper limit lower than "up to 5". .

All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety, as if fully set forth herein.

The interpolymer portion of the polymer will be described first, followed by the second polymer portion, and then the coupling of the two polymer portions to form the polymer.

Interpolymers contain unsaturation resulting from the incorporation of polyenes, especially dienes and trienes (eg, myrcene). C ₄ -C ₁₂ conjugated dienes such as, but not limited to, 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, and 1,3-hexadiene. preferable.

Polyenes can be incorporated into polymer chains in multiple ways. In some embodiments, the polymer chain has an overall 1,2-(vinyl) microstructure of about 10 to about 80%, or about 25 to about 65%, expressed as a numerical percentage based on the total polyene content. may be desirable. Substantially linear polymers have an overall 1,2-microstructure of about 50% or less, preferably about 45% or less, more preferably about 40% or less, even more preferably, based on the total polyene content. It is about 35% or less, most preferably about 30% or less. For certain end uses, it may be desirable to keep the content of 1,2-bonds even lower, such as less than about 7%, less than 5%, less than 2%, or less than 1%. By controlling the initial vinyl content, the amorphous nature of the interpolymer can be maintained, thereby avoiding crystallization, which can reduce the performance of vulcanizates made from rubber compounds containing polymers. reduce the degree of (Vinyl content and other microstructural details can be determined, for example, by proton NMR.)

Pendant aromatic groups may be provided by incorporating vinyl aromatic mer units, particularly C ₈ -C ₂₀ vinyl aromatics such as styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, and vinylnaphthalene. I can do it. When used with one or more polyenes, mer units with pendant aromaticity can be up to about 60%, about 1 to about 50%, about 10 to about 45%, about 20% of the total number of mer units in the polymer chain. to about 35%, or about 25 to about 30%.

The various types of mer in the interpolymer are preferably randomly incorporated, meaning that each type of mer does not form blocks, but is instead incorporated in a substantially non-repetitive manner. Random microstructures can provide certain benefits in some end uses, such as, for example, rubber compositions used in making tire treads.

Exemplary interpolymers include those having one or more polyenes and styrene-derived mers, such as poly(styrene-co-butadiene), also referred to as SBR.

Such interpolymers, particularly those made according to anionic techniques (described below), generally have an M _n of up to about 500,000 Daltons. In certain embodiments, M _n may advantageously be at least about 10,000 Daltons, or from about 50,000 to about 250,000 Daltons, or from about 75,000 to about 150,000 Daltons. It may be a range. A preferred range is about 75,000 to about 225,000 Daltons, especially about 100,000 to about 200,000 Daltons. Often, M _n will range from about 2 to about 150, more usually from about 2.5 to about 125, even more usually from about 5 to about 100, and most commonly about 10. A value such that the gum Mooney viscosity (ML ₄ /100° C.) is ˜75.

Interpolymers can be made by any of a variety of polymerization techniques. Solution polymerization generally allows a higher degree of control over properties such as randomness, microstructure, but other techniques can also be used, such as emulsion polymerization. Solution polymerization has been around since approximately the mid-20th century, so its general aspects are known to those skilled in the art. Useful polymerization solvents include various _C5 - _C12 cyclic and acyclic alkanes and their alkylated derivatives, certain liquid aromatic compounds, and mixtures thereof; are aware of useful solvent options and combinations.

Anionic (living) polymerization requires an initiator rather than a catalyst. Exemplary initiators include organolithium compounds, particularly alkyllithium compounds. Examples of organolithium initiators include N-lithio-hexamethyleneimine; n-butyllithium; tributyltinlithium; dialkylaminolithium compounds such as dimethylaminolithium, diethylaminolithium, dipropylaminolithium, dibutylaminolithium; diethylaminopropyl and trialkylstanyllithium compounds with C ₁ -C ₁₂ , preferably C ₁ -C ₄ alkyl groups.

Multifunctional initiators, ie, initiators capable of forming polymers with more than one living end, can also be used. Examples of polyfunctional initiators include 1,4-dilithiobutane, 1,10-dilithiodecane, 1,20-dilithioeicosane, 1,4-dilithiobenzene, 1,4-dilithionaphthalene, 1,10 -dilithioanthracene, 1,2-dilithio-1,2-diphenylethane, 1,3,5-trilithio-pentane, 1,5,15-trilithioeicosane, 1,3,5-trilithiocyclohexane, 1 , 3,5,8-tetralithiodecane, 1,5,10,20-tetralithioeicosane, 1,2,4,6-tetralithiocyclohexane, and 4,4'-dilithiobiphenyl. Not limited to these.

In addition to organolithium initiators, so-called functionalized initiators may also be useful. These are incorporated into the polymer chain, thus providing a functional group at the starting end of the chain. Examples of such materials include lithiated arylthioacetals (see, e.g., U.S. Pat. No. 7,153,919), organolithium compounds, and optionally substituted Included are reaction products with N-containing organic compounds such as aldimines, ketimines, secondary amines (see, eg, US Pat. Nos. 5,153,159 and 5,567,815). Using N-atom-containing initiators, such as lithiated HMI, can further enhance the interaction between the polymer chains and the carbon black particles. See also, for example, U.S. Pat. I want to be

In solution polymerization, both randomization and vinyl content (ie, 1,2-microstructure) can be increased by including modifiers, usually polar compounds, in the polymerization components. Up to 90 or more equivalents of modifier can be used per equivalent of initiator, with the amount depending, for example, on the desired vinyl content, the level of non-polyene monomer used, the reaction temperature, and the particular conditioning used. Depends on the nature of the agent. Compounds useful as modifiers include organic compounds containing heteroatoms (eg, O or N) with nonbonding electron pairs. Examples include dialkyl ethers of mono- and oligo-alkylene glycols; crown ethers; tertiary amines such as tetramethylethylenediamine; THF; THF oligomers; 2,2-bis(2'-tetrahydrofuryl)propane, dipiperidylethane. , hexamethylphosphoramide, N,N'-dimethylpiperazine, diazabicyclooctane, diethyl ether, tributylamine, etc. ).

Although those skilled in the art will understand the conditions typically used in anionically initiated polymerizations, a representative description is provided for convenience. The following is based on a batch process, but can be extended to semi-batch, continuous, or other approaches.

The blend of monomers and solvent can be placed in a suitable reaction vessel, followed by the addition of modifiers (if used) and initiators, which are often added as part of a solution or blend. Alternatively, monomers and modifiers can be added to the initiator. The reaction can be heated (typically below about 150° C.) and stirred.

After introduction of the starting compound, under anhydrous and oxygen-free conditions, a period sufficient to form the desired polymer, typically from about 0.01 hour to about 100 hours, more typically from about 0.08 hour to about Polymerization is allowed to proceed for 48 hours, typically from about 0.15 hours to about 2 hours.

After reaching the desired degree of conversion, the heat source (if used) can be removed and the reaction mixture can be transferred to a post-polymerization vessel for functionalization if the reaction vessel is reserved for polymerization only.

Interpolymers prepared according to anionic techniques have active ends (or at least two active ends if a multifunctional initiator is used). When using polymerization techniques that do not provide at least one active end, it is necessary to make at least a portion of the polymer chain reactive so that functionalization can occur.

Functionalization of the active end can provide a terminal moiety, preferably a terminal moiety directly attached to the interpolymer. The terminal moiety provided must be reactive with (or contain a functional group reactive to) the carbanion and must be capable of (or contain a functional group capable of interacting with) the silica. (including groups) is required. Preferably, the terminal moiety also does not react or degrade when the interpolymer to which it is attached is exposed to hydrogenation conditions.

Using terminally activated interpolymers as exemplary materials, functionalization can be easily accomplished by reaction with compounds capable of providing the aforementioned terminal moieties. One non-limiting example of such a compound is a compound that contains both epoxy and siloxy groups. In some embodiments, the siloxy group can be a trialkoxysilane in which the alkyl portion contains 1 to 6 C atoms, preferably 1 to 3 C atoms. Trimethoxysilane is preferred. An exemplary functionalizing compound is 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (ECETMOS).

If desired, the cement containing the functionalized interpolymer can be deactivated in a suitable active hydrogen atom-containing solvent. Furthermore, if the polymer cement itself is not hydrogenated, it can be processed (drying, sheeting, etc.) and stored.

The functionalized interpolymer is prepared with a hydrogenation catalyst, often Ni (e.g., nickel octoate), in the presence of a stream of H ₂ in a suitable organic liquid and/or with additional organic liquid added thereto. Alone or in combination with an Al-containing compound (for example, an organoaluminum compound such as a trialkylaluminium). The solvent can include one or more of the aforementioned organic liquids. When the catalyst contains both Ni and Al, the Al/Ni molar ratio is between 1:1 and 5:1, preferably between 2:1 and 4:1, most preferably between 3:1±20% (i.e. 2 .4:1 to 3.6:1).

The pressurized H ₂ is about 0.1 to about 10 MPa (1 to 100 atm), typically about 0.25 to about 7.5 MPa (2.5 to 74 atm), typically about 0.5 It can be introduced at ~5 MPa (5 to 50 atmospheres).

Extent of hydrogenation refers to the mole percent of polyene double bonds lost after an interpolymer undergoes a hydrogenation process such as those described above, and ranges from approximately 50% to 100% as determined by ^T H NMR spectroscopy. It can be up to close range. A degree of hydrogenation of at least 80%, 84%, 88%, 92%, or 96% may be desirable in view of certain mechanical properties of vulcanizates made from rubber compounds containing interpolymers.

Hydrogenation reduces the number of double bonds in both the main and side chains of each polymer. The degree of hydrogenation of each type of unsaturation tends to be approximately equal.

If desired, the cement containing the hydrogenated functionalized interpolymer can be processed (dried, sheeted, etc.) and stored if the interpolymer cement itself is not used for reaction with the second type of polymer.

The second type of polymer has terminal functional groups and is therefore provided by anionically initiated polymerization, the general conditions of which are described above.

A second type of polymer includes unsaturation resulting from the incorporation of polyenes, especially dienes and trienes (eg, myrcene). C ₄ -C ₁₂ conjugated dienes such as, but not limited to, 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, and 1,3-hexadiene preferable. Other types of mers that can be incorporated include monoolefin monomers, such as those obtained from the vinyl aromatics described above and α-olefins (eg, ethylene and propylene), as well as mixtures of the foregoing. The amount of monoolefin mer is generally kept below 20%, usually below 15%, typically below 10%, and most typically below 5%. Preference is given to embodiments in which the polymer comprises only polyenes, in particular only conjugated diemers, among which homopolymers are particularly preferred.

The second polymer is typically synthesized to have a molecular weight substantially lower than that of the (hydrogenated) interpolymer described above. The M _n of the second polymer is typically less than 75,000 Daltons, generally from about 5000 to about 50,000 Daltons. Some embodiments have an M _n of about 10,000 to about 20,000 Daltons, particularly about 12,000 to about 15,000 Daltons, and other embodiments have an M _n of about 30,000 Daltons. ~about 40,000 Daltons.

The microstructure of the second polymer can vary widely without significantly affecting the process.

The second polymer is not hydrogenated, functionalized, or (intentionally) deactivated, so it retains terminal activity.

When the two aforementioned types of polymers are introduced, the latter reacts with the terminal functional groups of the former. The reaction is carried out at a temperature of about 0°C to about 150°C, generally about 10°C to about 100°C, typically about 20°C to about 80°C, for 10 to 600 minutes, typically 30 to 300 minutes. It can be advanced. Although catalysis is not required, it is preferable to maintain oxygen-free and anhydrous conditions to maintain the activity of the carbanionic polymer chains.

As will be understood by those skilled in the art, the amount of chains and the ratio of the two types of polymers can be used to control the coupling reaction. Assuming that the interpolymer is prepared using an anionic (e.g., n-BuLi) initiator and all or nearly all of its chains are functionalized, the ratio of Li used in the two polymerizations is: It can be used as a surrogate to adjust the amounts of the two types of polymers involved in the coupling reaction. The ratio of the second polymer to the first polymer may range from 1:2 to 10:1, with ratios of 1:1 to 5:1, even about 3:1 being more common. .

Once this coupling reaction is complete, a polymer is obtained. Thus, the polymer includes a hydrogenated interpolymer portion, a non-hydrogenated polymer portion, and a functional group covalently bonded between the two polymer portions. This functional group shows interaction with the silica filler.

The polymer typically has an M _n of about 250,000 to about 600,000 Daltons, often about 350,000 to about 550,000 Daltons.

The majority of the conjugated diemer in the entire polymer is preferably incorporated in the 1,2-(ie, vinyl) configuration.

The polymers in vulcanizable compositions include, but are not limited to, natural or synthetic polyisoprene, and a wide variety of other polymers, including homopolymers and interpolymers of polyenes, particularly dienes, most particularly conjugated dienes. Can be used as an ingredient. This has been found to be particularly useful when used with BR having a 1,2-vinyl content of 3% or less and a cis-1,4 content of at least 96%. (In this paragraph, all percentages are moles; such percentages are determined by spectroscopic techniques.) When used with one or more polymers of this type, the polymer is 2:3 to 3:2; Preferably, a ratio of 3:4 to 4:3, more preferably 4:5 to 5:4, most preferably 1:1 to 9:8 can be used.

Any other polymer can be used in any suitable amount that does not interfere with the ability of the resulting rubber composition to provide a vulcanizate with the desired physical properties. Non-limiting examples include butyl rubber, neoprene, EPR, acrylonitrile/butadiene rubber, silicone rubber, fluoroelastomers, ethylene/acrylic rubber, EVA, epichlorohydrin rubber, chlorinated polyethylene rubber, chlorosulfonated polyethylene rubber, hydrogenated Examples include nitrile rubber and tetrafluoroethylene/propylene rubber.

Polymers of the above-mentioned type can be formulated in particular with reinforcing fillers. The elastomeric compound is typically loaded to a volume fraction of the total volume of added filler divided by the total volume of elastomer stock (often about 25%), which is typical of reinforcing fillers ( (combined) amounts range from about 30 to about 100 phr, with the upper end of this range depending primarily on how effectively the processing equipment can handle the increased viscosity that occurs when such fillers are used. It is decided.

Useful fillers include various forms of carbon black, including, but not limited to, furnace black, channel black, and lamp black. More specifically, examples of carbon blacks include super abrasion resistant furnace black, high abrasion resistant furnace black, high speed extrudability furnace black, fine furnace black, intermediate super abrasion resistant furnace black, semi-reinforced furnace black, Examples include medium processability channel black, difficult processability channel black, conductive channel black, and acetylene black, and mixtures of two or more of these may be used. Carbon blacks having a surface area (EMSA) of at least 20 m ² /g, preferably at least about 35 m ² /g are preferred; see ASTM D-1765 for methods of measuring carbon black surface area. Although the carbon black may be in pelletized form or in non-pelletized flocs, non-pelletized carbon black may be preferred for use in certain mixers.

The amount of carbon black can be up to about 50 phr, typically 5 to 40 phr.

Amorphous silica (SiO ₂ ) can also be utilized as a filler. Silica is generally classified as wet-process hydrated silica because it is produced by a chemical reaction in water, from which it is precipitated as ultrafine spherical particles. These primary particles associate strongly into aggregates, which in turn combine more weakly into clumps. A "highly dispersible silica" is any silica that has a very large ability to deagglomerate and disperse in an elastomeric matrix, which can be observed by thin section microscopy.

Surface area is a reliable indicator of the reinforcing properties of various silicas and is described by the Brunauer, Emmet and Teller ("BET") method (J. Am. Chem. Soc., vol. 60, p. 309 et seq.) is an accepted method for measuring surface area. The BET surface area of silica is generally less than 450 m ² /g, typically from about 32 to about 400 m ² /g, or from about 100 to about 250 m ² /g, or from about 150 to about 220 m ² /g.

The pH of the silica filler (if used) is generally about 5 to about 7 or slightly higher, preferably about 5.5 to about 6.8.

When using silica, coupling agents such as silanes are often added to ensure good mixing in and interaction with the elastomer. Generally, the amount of silane added ranges from about 4 to 20 weight percent, based on the weight of silica filler present in the elastomeric compound. The coupling agent can have the general formula α-TG, where A can be physically and/or chemically bonded to groups on the surface of the silica filler (e.g., surface silanol groups). Represents a functional group. T represents a hydrocarbon group bond and G represents a functional group that can be bonded to the elastomer (eg, via a sulfur-containing bond). Such coupling agents include organosilanes, particularly polysulfurized alkoxysilanes (e.g., U.S. Pat. Nos. 3,873,489; 3,978,103; 3,997,581; , No. 002,594, No. 5,580,919, No. 5,583,245, No. 5,663,396, No. 5,684,171, No. 5,684,172 , No. 5,696,197), or polyorganosiloxanes having the above-mentioned G and A functional groups. Addition of processing aids can reduce the amount of silane used; see, for example, US Pat. No. 6,525,118 for a discussion of fatty acid esters of sugars used as processing aids. Additional fillers useful as processing aids include mineral fillers such as clay (hydrated aluminum silicate), talc (hydrated magnesium silicate), and mica, as well as non-mineral fillers such as urea _{and Na2SO4} . These include, but are not limited to: Exemplary mica primarily includes alumina, silica, and potash, although other varieties may also be used. Additional fillers can be used in amounts up to about 40 phr, typically up to about 20 phr.

Silica is generally used in amounts up to about 100 phr, typically from about 5 to about 80 phr. If carbon black is also present, the amount of silica can be reduced to a minimum of 1 phr, and reducing the amount of silica reduces the amount of processing aids and silane (if present) that can be used.

One or more non-conventional fillers with relatively high interfacial free energies, ie surface free energy values in water (γ _p1 ), can be used with or in place of carbon black and/or silica. The term "relatively high" includes, for example, at least about 300, at least about 400, at least about 500, at least about 600, at least about 700, at least about 750, at least about 1000, at least about 1500, and at least about 2000 mJ/ ^m2. γ _p1 value of amorphous silica, e.g., greater than the value of the water-air interface, preferably several times that value (e.g., at least 2 times, at least 3 times, or at least 4 times) (e.g., at least 2 times, at least 3 times, at least 4 times, at least 5 times, at least 6 times, at least 7 times, at least 8 times, at least 9 times, or at least 10 times). can be defined or characterized. Non-limiting examples of naturally derived materials with relatively high interfacial free energy include F-apatite, goethite, hematite, sphenorite, cuprite, gibbsite, quartz, kaolinite, all forms of pyrite, etc. can be mentioned. Certain synthetic complex oxides can also exhibit this type of high interfacial free energy.

Materials of the aforementioned type are typically denser than carbon black or amorphous silica, and therefore replacing a given mass of carbon black or silica with an equal mass of non-conventional filler typically In effect, the total volume of filler present in a given compound is much less. Therefore, replacements are typically made with equal volumes rather than equal weights.

Other conventional rubber additives may also be added. For example, these include process oils, plasticizers, antioxidants such as antioxidants and antiozonants, hardeners, and the like.

All ingredients can be mixed in standard equipment such as a Banbury mixer or a Brabender mixer. Typically, mixing is done in two or more stages. During the first stage (often referred to as the masterbatch stage), mixing typically begins at a temperature of about 120 to about 130°C and increases until a so-called drop temperature (typically about 165°C) is reached. do.

If the formulation contains fillers other than or in addition to carbon black, a separate regrind step is often used to separately add the silane component. This stage is often carried out at temperatures similar to, but often slightly lower than, those used in the masterbatch stage, i.e. up to a drop temperature of about 90°C to about 150°C. Increase temperature.

Reinforced rubber compounds are conventionally cured with about 0.2 to about 5 phr of one or more known vulcanizing agents, such as sulfur- or peroxide-based cure systems. For a general disclosure of suitable vulcanizing agents, the interested reader may refer to Kirk-Othmer, Encyclopedia of Chem. Tech. , 3d ed. , (Wiley Interscience, New York, 1982), vol. 20, pp. See summaries such as those provided at 365-468. Vulcanizing agents, accelerators, etc. are added at the final mixing stage. To reduce the possibility of undesirable charring and/or premature onset of vulcanization, this mixing step is often conducted at lower temperatures, such as starting at about 60°C to about 65°C and starting at about 105°C. ℃ to about 110℃.

The compounded mixture is then processed (e.g., milled) into sheets and formed into any of the various components, which are then vulcanized; this vulcanization is typically used during the mixing stage. The temperature is about 5° C. to about 15° C. higher than the maximum temperature to be used, most commonly about 170° C.

As will be apparent from the foregoing, general preferences with respect to features, ranges, numerical limitations and embodiments may be superseded, to the extent practicable, by other such generally preferred features, provided that they do not interfere or are incompatible. It is contemplated that ranges and numerical limitations may be combined. To help envision some such combinations, we provide the following sequential embodiments.

Process embodiment P1. A process for providing a functionalized polymer comprising a hydrogenated interpolymer portion and a non-hydrogenated polymer portion, the process comprising:
a) a terminally functionalized interpolymer comprising a vinyl aromatic mer, a conjugated diemer, a hydride of the conjugated diemer, and a terminal functional group containing a functional group that is reactive towards carbanions and capable of interacting with silica; steps to provide;
b) introducing the interpolymer into a carbanionic polymer containing a conjugated diemer, or introducing a carbanionic polymer into the interpolymer;
c) reacting the carbanionic polymer with the terminal functional group to provide the functionalized macromolecule.
P2. The process of P1, wherein the interpolymer is provided by subjecting a terminally functionalized polymer comprising a vinyl aromatic mer and a conjugated diemer to hydrogenation conditions to hydrogenate at least 50 mole percent of the conjugated diemer.
P3. The end-functionalized polymer is provided by reacting a carbanionic interpolymer comprising a vinyl aromatic mer and a conjugated diemer with a compound capable of coupling the polymer chains, wherein the compound has a silica-interactive functional group. and is non-reactive and resistant to decomposition when exposed to hydrogenation conditions.
P4. The process according to P3, wherein the compound contains an epoxy group and a siloxy group.
P5. The process according to P4, wherein the compound is 2-(3,4-epoxycyclohexyl)ethyltrialkoxysilane.
P6. The process according to P5, wherein the alkoxy moiety of the compound is a methoxy moiety.
P7. The process according to P1, wherein at least 80 mole % of the conjugated diemer in the interpolymer is hydrogenated.
P8. The process according to P7, wherein at least 90 mole % of the conjugated diemer in the interpolymer is hydrogenated.
P9. The process according to any one of P1 to P8, wherein the interpolymer comprises 10 to 45 mole % styrenemer.
P10. The process according to any one of P1 to P9, wherein the majority of the conjugated diemer is incorporated in the 1,2-vinyl configuration.
P11. The process according to any one of P1 to P10, wherein the carbanionic polymer comprises a conjugated diemer.
P12. The process according to any one of P1 to P11, wherein 0.5 to 10 equivalents of the carbanionic polymer are reacted per equivalent of the interpolymer.
P13. Process according to any one of P1 to P12, wherein the carbanionic polymer has a number average molecular weight of 5 to 50 kg/mol.
P14. The process according to P13, wherein the carbanionic polymer has a number average molecular weight of 10 to 20 kg/mol.
P15. The process according to P13, wherein the carbanionic polymer has a number average molecular weight of 30 to 40 kg/mol.

Polymer embodiment M1. A functionalized polymer comprising a hydrogenated interpolymer moiety, a non-hydrogenated polymer moiety, and a functional group covalently bonded to each of the moieties, wherein the functional group exhibits interaction with silica.
M2. The functionalized polymer according to M1, wherein the functional group is a radical of a compound containing an epoxy group and a siloxy group.
M3. The functionalized polymer according to M1, wherein the compound is 2-(3,4-epoxy-cyclohexyl)ethyl tritrikoxysilane.
M4. The functionalized polymer according to M1, wherein the alkoxy moiety of the compound is a methoxy moiety.
M5. Functionalized polymer according to any one of M1 to M4, wherein the interpolymer comprises a vinyl aromatic mer and a conjugated diemer.
M6. The functionalized polymer according to M5, wherein the interpolymer consists of a vinyl aromatic mer and a conjugated diemer.
M7. The functionalized polymer according to M5 or M6, wherein at least 80 mole % of the conjugated diemer in the interpolymer is hydrogenated.
M8. The functionalized polymer according to M7, wherein at least 90 mole % of the conjugated diemer in the interpolymer is hydrogenated.
M9. Functionalized polymer according to any one of M5 to M8, wherein the interpolymer contains 10 to 45 mole % styrene.
M10. Functionalized polymer according to any one of M5 to M9, wherein the majority of the conjugated diemer is incorporated in a 1,2-vinyl configuration.
M11. The functionalized polymer according to any one of M1 to M10, wherein the non-hydrogenated polymer portion comprises a conjugated diemer.
M12. The functionalized polymer according to M11, wherein the non-hydrogenated polymer portion consists of a conjugated diemer.
M13. The functionalized polymer according to any one of M1-M12, wherein the polymer comprises a plurality of non-hydrogenated polymeric moieties.
M14. Functionalized polymer according to any one of M1 to M12, wherein the non-hydrogenated polymer portion is obtained from a conjugated diene homopolymer having a number average molecular weight of 5 to 50 kg/mol.
M15. Functionalized polymer according to M14, wherein the conjugated diene homopolymer has a number average molecular weight of 10 to 20 kg/mol or 30 to 40 kg/mol.

Embodiment of rubber compound R1. A composition comprising a functionalized polymer according to any one of M1 to M15 and at least one bulk rubber.
R2. The composition according to R1, wherein the at least one bulk rubber comprises polybutadiene.
R3. The composition according to R2, wherein the at least one bulk rubber is polybutadiene.
R4. The composition according to R2 or R3, wherein the polybutadiene has at least 90% of its mers in the cis configuration.
R5. The composition according to any one of R1 to R4, further comprising a particulate filler comprising silica.
R6. The composition according to any one of R1 to R5, further comprising a heat-activated crosslinking agent and a vulcanizate obtained from such a composition.

The following non-limiting and illustrative examples provide detailed conditions and materials that may be useful in the practice of the present invention. In these examples, 1 as the exemplary polyene was selected due to various factors including cost, availability, handling ability, and most importantly, the ability to make internal comparisons and comparisons with previously reported polymers. ,3-butadiene and styrene as an exemplary vinyl aromatic compound. Those skilled in the art can extend these examples to a variety of homopolymers and interpolymers.

In the following examples, the n-butyllithium (n-BuLi) solution is 2.5M (1.6M in Example 9) and the 2,2-bis(2'-tetrahydrofuryl)propane (BTHFP) solution is 1.5M. 6M and both are hexane solutions.

Example 1: Functionalized SBR
In a 5 gallon N2 _- purged reactor equipped with an agitator, 3.99 kg hexane, 1.98 kg styrene solution (30.3% (w/w) in hexane), and 5.41 kg A solution of 1,3-butadiene (20.6% (w/w) in hexane) was added. The reactor jacket was then heated to 50° C. after charging 5.72 mL of n-BuLi solution followed by 2.23 mL of BTHFP solution.

The batch temperature peaked at about 80°C after about 39 minutes.

After approximately 40 additional minutes, 3.31 mL of ECETMOS was added to the reactor to functionalize the carbanionic polymer chains. After about 30 minutes, 1.31 mL of isopropanol was added to stop the polymerization.

A sample of the polymer cement was collected approximately 10 minutes after stopping and the remaining cement was transferred to a storage container. The properties of the functionalized SBR intermediates collected are summarized in Table 2 below.

Example 2: Hydrogenation 11.43 kg of the functionalized polymer from Example 1 (in hexane) was introduced into a stirred reactor of approximately 44 L (11.7 gallons) under a _N2 atmosphere, followed by 5.315 kg of hexane. , a 10.0% (w/w) solution was obtained. After purging the reactor three times with 138 kPa (20 psi) of _H2 , the reactor jacket was heated to 50 °C.

Add 400 mL of hexane and 21.97 mL of 1.03 M triethylaluminum to a dry bottle purged with _N2 , followed by the addition of 3.99 mL of nickel octoate solution (10.1% (w/w) in hexane). A hydrogenation catalyst system (Al/Ni=3.3:1) was obtained.

The catalyst system was charged to the reactor and the reactor was immediately pressurized to 75 psi with _H2 .

After approximately 90 minutes, the _H2 was vented from the reactor and the polymer cement was transferred to a storage container. Approximately equal amounts of this polymer cement were transferred to previously collected 750 mL _N2 purged glass bottles.

The percentage hydrogenation of the butadiene mer was determined (by NMR) to be 92%.

Example 3: Low molecular weight BR
1.23 kg hexane and 3.255 kg 1,3-butadiene solution (20.9% (w/w) in hexane) in a 7.6 L (2 gallon) N ₂ purged reactor equipped with an agitator. added. The reactor was charged with 13.61 mL of n-BuLi solution followed by 0.53 mL of BTHFP solution.

The reactor jacket was heated to 57°C and the batch temperature peaked at about 82°C after 38 minutes. After a total reaction time of approximately 60 minutes, the reaction mixture was cooled to room temperature.

Examples 4-8: Coupling The polymer products of Examples 2 and 3 were coupled in various ratios as shown in the table below. (The ratio was determined based on the amount of Li of 0.00125mM/g polymer cement from Example 2 and 0.0075mM/g polymer cement from Example 3.)

The bottle was placed in a 50°C water bath and stirred for approximately 90 minutes. The samples were then agglomerated in a mixture of isopropanol and butylated hydroxytoluene (BHT). The agglomerated polymer samples were drum dried at 120°C.

The properties of the polymers from the previous examples are shown in the table below. The molecular weight values (all kg/mol) of the polymer samples were determined by GPC using THF as solvent and calibrated with a series of polystyrene standards. The styrene and 1,2-bond (vinyl) contents of the polymer samples were determined by NMR spectroscopy, and the glass transition temperature (T _g ) values were determined by DSC.

Example 9: Low molecular weight BR
0.806 kg hexane and 1.071 kg 1,3-butadiene solution (24.1% (w/w) in hexane) in a 3.8 L (1 gallon) N ₂ purged reactor equipped with an agitator. added. The reactor was charged with 26.58 mL of n-BuLi solution followed by 5.32 mL of BTHFP solution.

The reactor jacket was heated to 57°C and the reaction was allowed to proceed for 30 minutes.

Example 10: Coupling To 500 mL of the polymer cement from Example 2 were added 12 mL of the product of Example 9. This resulted in a 2:1 equivalence ratio based on the amount of Li in each of the 0.00125mM/g polymer cement from Example 2 and the 0.01875mM/g polymer cement from Example 9 (Examples 2-3). 9) was obtained.

The bottle was placed in a 50°C water bath and stirred for approximately 90 minutes. The samples were then agglomerated in a mixture of isopropanol and BHT. The agglomerated polymer samples were drum dried at 120°C.

The properties of the products of the coupling reaction are shown in the table below, where each unit is as described above and the properties were determined as above.

Examples 11-13: Rubber compounds and vulcanizates Using unfilled rubber composition formulations containing waxes, antioxidants, accelerators, curing agents, etc., three types differing only in the nature and amount of the included polymers. A rubber compound was prepared (Example 11 is a comparative example).
Example 11, 50 pbw high cis BR and 50 pbw polymer of Example 2 Example 12, 45 pbw high cis BR and 55 pbw polymer of Example 10 Example 13, 45 pbw high cis BR, 49.5 pbw example 2 and 5.5 pbw of the polymer of Example 10.

Each formulation included a masterbatch and final mixing step, exposing each compound to standard curing time and temperature combinations.

The fracture stress and toughness of the resulting vulcanizates were evaluated both at room temperature (RT, approximately 22°C) and 100°C, and the results are summarized in the table below.

From the above, it can be seen that using a polymer of the type of Example 10 as an additive (e.g., at 5 phr) improves tensile properties, but using it as a direct replacement for functionalized H-SBR essentially It can be seen that equivalent characteristics can be obtained.

For the vulcanizates of Example 11 and Example 12, tan6 was plotted against temperature over the range of -120°C to -100°C. Comparing the peaks of the two vulcanizates in the range of about -80°C to -100°C shows that the peaks of the vulcanizate of Example 12 both decrease and fluctuate by about +3°C; Both indicate that the miscibility between high-cis BR and H-SBR is improved when the latter contains grafted BR segments.

The improved miscibility was confirmed by transmission electron microscopy, and images showed that the vulcanizate of Example 12 had less discrete domains than the vulcanizate of Example 11, and that overall polymer mixing was improved. It was shown to be good.

Claims (20)

A functionalized polymer comprising a hydrogenated interpolymer portion, a non-hydrogenated polymer portion, and a functional group covalently bonded to each of said portions, said functional group exhibiting interaction properties with silica. The functionalized polymer according to claim 1, wherein the functional group is a radical of a compound containing both an epoxy group and a siloxy group. The functionalized polymer of claim 2, wherein the compound is 2-(3,4-epoxy-cyclohexyl)ethyltrialkoxysilane and the alkoxy group is optionally a methoxy moiety. Functionalized polymer according to any one of claims 1 to 3, wherein the interpolymer comprises a vinyl aromatic mer and a conjugated diemer. 5. The functionalized polymer of claim 4, wherein at least 80 mole percent of the conjugated diemer in the interpolymer is hydrogenated. 6. The functionalized polymer of claim 5, wherein at least 90 mole percent of the conjugated diemer in the interpolymer is hydrogenated. 5. The functionalized polymer of claim 4, wherein the interpolymer comprises 10 to 45 mole percent styrene. 5. The functionalized polymer of claim 4, wherein the majority of the conjugated diemer is incorporated in a 1,2-vinyl configuration. Functionalized polymer according to any one of claims 1 to 3, wherein the non-hydrogenated polymer portion consists of a conjugated diemer. Functionalized polymer according to any one of claims 1 to 3, wherein the polymer comprises a plurality of non-hydrogenated polymeric moieties. Functionalized polymer according to any one of claims 1 to 3, wherein the non-hydrogenated polymer portion is obtained from a conjugated diene homopolymer having a number average molecular weight of 5 to 50 kg/mol. Functionalized polymer according to claim 11, wherein the conjugated diene homopolymer has a number average molecular weight of 10-20 kg/mol. Functionalized polymer according to claim 11, wherein the conjugated diene homopolymer has a number average molecular weight of 30-40 kg/mol. A composition comprising a functionalized polymer according to any one of claims 1 to 3, at least one bulk rubber optionally comprising polybutadiene, and optionally silica. 15. The composition of claim 14, wherein the composition comprises at least one polybutadiene, at least 90% of which are in the cis configuration. A method of providing a functionalized polymer comprising a hydrogenated interpolymer portion and a non-hydrogenated polymer portion, the method comprising:
a)
1) a vinyl aromatic mer;
2) a conjugated diemmer;
3) a hydride of a conjugated diemer;
4) providing a terminally functionalized interpolymer comprising a terminal functional group that is carbanion-reactive and that includes a functional group that is capable of interacting with silica;
b) introducing said interpolymer into a carbanionic polymer comprising a conjugated diemer, or introducing said carbanionic polymer into said interpolymer, wherein said carbanionic polymer optionally contains between 5 and 50 kg/mol. having a number average molecular weight;
c) reacting the carbanionic polymer with the terminal functional group to provide the functionalized macromolecule. 17. The interpolymer of claim 16, wherein the interpolymer is provided by subjecting a terminally functionalized polymer comprising a vinyl aromatic mer and a conjugated diemer to hydrogenation conditions to hydrogenate at least 50 mole percent of the conjugated diemer. Method. 18. The method of claim 17, wherein at least 80 mole percent of the conjugated diemer is hydrogenated. 19. The method of claims 16-18, wherein at least one of the following is true: the interpolymer contains 10 to 45 mole % styrene mer, and the majority of the conjugated diemer is incorporated in the 1,2-vinyl configuration. The method described in any one of the above. A method according to any one of claims 16 to 18, wherein 0.5 to 10 equivalents of the carbanionic polymer are reacted per equivalent of the interpolymer.